Now imagine this drawing your weapon and LX2 and trying to keep it on hi for 3-5 minutes using your thumb.Your thumb will tire fast.Now imagine if its a longer stop/standoff you'll have to try and twist the tailcap 340 degrees while holding your weapon taking eyes off of the threat. Just to keep it in hi mode.No LEO should ever have to take eyes off a threat to change modes on a Flashlight.
Now the E2DL has a push button tactical forward with clicky. Push it in for momentary or all the way in and click it and your still in Hi mode.No twisting thumbing around and your eyes are on the Target at all times.
I won't argue that there are definitely preferences a person might have, and advantages and disadvantages between the 2 stage twist and the 2 stage click interfaces Surefire uses. However, I really can't imagine why you'd take your eyes off the target to activate or change levels on the LX2 - I use one every day and operate it one handed without ever looking at it.
I freely admit that I have NO IDEA how well that would work with a firearm - I don't use or carry a firearm, but I can't really see how operating it would require you to take your eyes off the target.
I think it would depend on how you plan to grip the light while using it, particularly with a pistol. I can switch twist the LX2 tailcap one handed no problem in either an overhand grip (twisting the cap between my thumb and forefinger), or with an underhand grip (gripping the cap with my 3rd finger and twisting the body of the light.)
If your grip is a cigar type grip, where you really only have your thumb to use, you can definitely switch levels by pressing, but you have to hold it. (No clue if that's a big deal or not - I really have no idea how long one would train a pistol on someone.) In that type of grip, there is almost no way I can twist the light to lock in a level. I have no personal experience with this, but I can't imagine that holding a pistol makes that any easier. (So I think you are 100% right about that!)
Anyway, I know people understand this stuff, and sorry to belabor a point. But I do think it comes down to how you like to carry / use the light, and what's natural and comfortable for you.
Believe it or not, I actually prefer clicky tail caps, and yet despite that, I find that I keep going back to the LX2 because it is just so perfect. Operating it is VERY natural and comfortable, at least to me. The two light levels it offers seem perfect for my uses too. (Again, my uses are WAY less stressful than that of a LEO or paramedic, although I am out in the dark quite often.) I honestly find some of the click to switch mode lights I have to be somewhat annoying to use. (Not trying to say anyone is right or wrong here - I think either light is reasonably well designed for military / LEO use, and maybe it just comes down to fit / preference / training etc.)